I have to disagree with the first point, I work for a company that develops a lot of big (and small) Yahoo stores. There is a large amount of customisation possible, it is great value and also scales for big sites. The main advantage is that you are running straight away and that you get all the traffic pushed from the Yahoo network (which can be considerable and some big players have Yahoo stores in addition to their main sites just to attract this traffic).

Thanks for the info on Yahoo store. My assumption was based on the relative uniformity of the sites I see on it. Also, you can't actually modify any code, right? So if you wanted a special feature, like a gift registry that would give discounts to people who buy from it or a special offer for customers who meet certain conditions, you can't really do it yourself.

Maybe you could update your answer with some information on the flexibility and limitations of the Yahoo option?

Unfortunatly by default Yahoo stores tend to look alike. You get the left nav buttons and a pretty basic look. You get to use templates (which basically involves programming in lisp (but point and click (without the brackets))). A couple of examples:

BargainCo - I just chose this at random from the list of sites, more or less a default

Alight - one I've worked on, uses templates and some tricks like HTML embedded in the templates. Uses other trickery like a perl script which takes the whole store and re-creates it with the 'trails' and paging which Yahoo doesn't support.

Back to the point. Basically you can't do a lot of that stuff. Well you can, but it involves a bit of hackery. You can use some javascript trickery and external CGIs to get around some of these problems. The traffic generated by the Yahoo network makes it worthwhile for most people.

On the other hand, most stores don't want advanced features and for $50/month Yahoo provides a fantastic deal for small stores.

We use Intershop for sites that need features Yahoo can't provide. It's a great product but it is thousands of dollars just for the software before you start thinking about buying servers, hosting, development etc.